1. Field of the Invention (Technical Field):
The present invention relates insensitive munitions and methods of making same.
2. Description of Related Art
Note that the following discussion refers to a number of publications by author(s) and year of publication, and that due to recent publication dates certain publications are not to be considered as prior art vis-a-vis the present invention. Discussion of such publications herein is given for more complete background and is not to be construed as an admission that such publications are prior art for patentability determination purposes.
Many penetrator designs are able to achieve their penetration requirements with case walls not sufficiently thick to protect them from certain threats such as bullet and fragment impact and sympathetic detonation. Eliminating or reducing these threats are necessary to producing insensitive munitions (“IM”). However, it is impractical to make the case walls sufficiently thick to prevent detonation from unplanned stimuli. To reach IM goals in the current state of the art, protective barriers are included in shipping containers and reduced sensitivity explosives are employed. The addition of protective barriers in shipping containers imposes additional weight and cost, with no added value to munition performance.
For example, pumice has been employed as a sympathetic detonation barrier, as described in U.S. Pat. No. 5,160,468, entitled “Method for Preparing a Storage Container for Explosive Rounds” and U.S. Pat. No. 5,158,173, entitled “Weapons Storage Container to Prevent Sympathetic Detonation of Adjacent Weapons”, both to Halsey et al., which describe and cover the use of pumice as a tool for stopping sympathetic detonation of stored munitions. This technique is also described in Kandell et al., “Pumice as a Sympathetic Detonation Barrier”, 44th Annual Fuze Conference, National Defense Industrial Association (2000). Kandall et al. also describe the use of pumice as a sympathetic detonation barrier in “Development of a Sympathetic Detonation (SD) Barrier for JSOW and the Technological Aspects of Pumice as a Barrier to SD,” NATO IM Workshop, Oct. 1, 2003.
The present invention incorporates pumice within the munition itself by employing pumice inserts in a class of munitions known as “cased” or “shrouded”. The following references are representative of the state of the art with respect to shrouded munitions: U.S. Pat. No. 6,389,977, entitled “Shrouded Aerial Bomb”; U.S. Pat. No. 6,408,762, entitled “Clamp Assembly for Shrouded Aerial Bomb”; U.S. Patent No. D438,930, entitled “Shrouded Aerial Bomb”; and U.S. Pat. No. 6,374,744, entitled “Shrouded Bomb”; all to Schmacker et al.